added compat module and functions

Signed-off-by: lns <matzeton@googlemail.com>

11 files changed, 233 insertions, 53 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b3c929d..c570823 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -66,4 +66,4 @@ cppcheck:
   stage: analysis
   script:
     - pacman -Syu --noconfirm cppcheck
-    - cppcheck --enable=all --inconclusive --std=posix .
+    - cppcheck --force --enable=warning,unusedFunction,performance,portability --inconclusive --std=posix -DNDEBUG=1 -DHAVE_STRTOK_R=1 -DHAVE_LOCALTIME_R=1 -DHAVE_GETPWNAM_R=1 -DHAVE_GETGRNAM_R=1 .
diff --git a/.travis.yml b/.travis.yml
index 69b2f98..6f43ffe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,7 @@ compiler:
 - gcc
 before_install:
 - sudo apt-get -qq update
-- sudo apt-get install -y -qq coreutils make autoconf automake gcc pkg-config valgrind
+- sudo apt-get install -y -qq coreutils make autoconf automake gcc pkg-config valgrind cppcheck
   wget libssl-dev
 - wget 'https://www.libssh.org/files/0.7/libssh-0.7.5.tar.xz' -O ./libssh-0.7.5.tar.xz
 - tar -xvf ./libssh-0.7.5.tar.xz
@@ -21,6 +21,7 @@ script:
 - TERM=linux valgrind --error-exitcode=1 ./src/potd --test --redirect 127.0.0.1:2222:127.0.0.1:22222
   --protocol 127.0.0.1:22222:127.0.0.1:33333 --jail 127.0.0.1:33333 --rofile /tmp/potd-rofile
   --rodir /tmp/potd-rodir --root / --netns-rundir /tmp/potd-netns --ssh-rundir /tmp/potd-ssh
+- cppcheck --force --enable=warning,unusedFunction,performance,portability --inconclusive --std=posix -DNDEBUG=1 -DHAVE_STRTOK_R=1 -DHAVE_LOCALTIME_R=1 -DHAVE_GETPWNAM_R=1 -DHAVE_GETGRNAM_R=1 .
 env:
   global:
     secure: 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
diff --git a/configure.ac b/configure.ac
index bd51074..f97323d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -135,6 +135,8 @@ AC_CHECK_FUNCS([open read write close mmap munmap malloc free memset memcpy fork
                 setsockopt socket connect accept bind listen \
                 time localtime difftime strtol strtoll getopt_long_only], [],
       [ AC_MSG_ERROR([required function not available]) ])
+dnl check reentrant function availability
+AC_CHECK_FUNCS([strtok_r localtime_r getpwnam_r getgrnam_r])
 dnl GAI functions
 AC_CHECK_FUNCS([getaddrinfo getnameinfo freeaddrinfo], [],
       [ AC_MSG_ERROR([required GAI function not available]) ])
diff --git a/src/Makefile.am b/src/Makefile.am
index 1ac657b..c2fe07c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,5 +1,5 @@
 sbin_PROGRAMS = potd
-potd_SOURCES = utils.c options.c log.c log_colored.c log_file.c socket.c pevent.c capabilities.c filesystem.c jail.c forward.c redirector.c protocol.c protocol_ssh.c main.c
+potd_SOURCES = compat.c utils.c options.c log.c log_colored.c log_file.c socket.c pevent.c capabilities.c filesystem.c jail.c forward.c redirector.c protocol.c protocol_ssh.c main.c
 if HAVE_SECCOMP
 potd_SOURCES += pseccomp.c
 endif
diff --git a/src/compat.c b/src/compat.c
new file mode 100644
index 0000000..72c78a3
--- /dev/null
+++ b/src/compat.c
@@ -0,0 +1,104 @@
+/*
+ * compat.c
+ * potd is licensed under the BSD license:
+ *
+ * Copyright (c) 2018 Toni Uhlig <matzeton@googlemail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * - The names of its contributors may not be used to endorse or promote
+ *   products derived from this
+ *   software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "compat.h"
+
+
+char *
+potd_strtok(char *str, const char *delim, char **saveptr)
+{
+#ifdef HAVE_STRTOK_R
+    return strtok_r(str, delim, saveptr);
+#else
+    (void) saveptr;
+
+    return strtok(str, delim);
+#endif
+}
+
+struct tm *
+potd_localtime(const time_t *timep, struct tm *result)
+{
+#ifdef HAVE_LOCALTIME_R
+    return localtime_r(timep, result);
+#else
+    (void) result;
+
+    return localtime(timep);
+#endif
+}
+
+int
+potd_getpwnam(const char *name, struct passwd *pwd)
+{
+    struct passwd *result = NULL;
+
+    errno = 0;
+#ifdef HAVE_GETPWNAM_R
+    char buf[BUFSIZ];
+
+    return getpwnam_r(name, pwd, buf, sizeof buf, &result) || !result;
+#else
+    result = getpwnam(name);
+    if (result)
+        *pwd = *result;
+
+    return result == NULL;
+#endif
+}
+
+int
+potd_getgrnam(const char *name, struct group *grp)
+{
+    struct group *result = NULL;
+
+    errno = 0;
+#ifdef HAVE_GETGRNAM_R
+    char buf[BUFSIZ];
+
+    return getgrnam_r(name, grp, buf, sizeof buf, &result) || !result;
+#else
+    result = getgrnam(name);
+    if (result)
+        *grp = *result;
+
+    return result == NULL;
+#endif
+}
diff --git a/src/compat.h b/src/compat.h
new file mode 100644
index 0000000..386b80e
--- /dev/null
+++ b/src/compat.h
@@ -0,0 +1,55 @@
+/*
+ * compat.h
+ * potd is licensed under the BSD license:
+ *
+ * Copyright (c) 2018 Toni Uhlig <matzeton@googlemail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * - The names of its contributors may not be used to endorse or promote
+ *   products derived from this
+ *   software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef POTD_COMPAT_H
+#define POTD_COMPAT_H 1
+
+#include <string.h>
+#include <time.h>
+#include <pwd.h>
+#include <grp.h>
+
+
+char *
+potd_strtok(char *str, const char *delim, char **saveptr);
+
+struct tm *
+potd_localtime(const time_t *timep, struct tm *result);
+
+int
+potd_getpwnam(const char *name, struct passwd *pwd);
+
+int
+potd_getgrnam(const char *name, struct group *grp);
+
+#endif
diff --git a/src/filesystem.c b/src/filesystem.c
index 3284dd4..fa94987 100644
--- a/src/filesystem.c
+++ b/src/filesystem.c
@@ -49,6 +49,7 @@
 #include <assert.h>
 
 #include "log.h"
+#include "compat.h"
 #include "utils.h"
 #include "options.h"
 
@@ -239,7 +240,7 @@ static MountData *
 get_last_mount(void)
 {
     FILE *fp = fopen("/proc/self/mountinfo", "r");
-    char *ptr;
+    char *ptr, *saveptr = NULL;
     int cnt = 1;
     size_t len;
 
@@ -265,11 +266,11 @@ get_last_mount(void)
     //		mdata.dir: /home/netblue/.cache
     //		mdata.fstype: tmpfs
     memset(&mdata, 0, sizeof(mdata));
-    ptr = strtok(mbuf, " ");
+    ptr = potd_strtok(mbuf, " ", &saveptr);
     if (!ptr)
         goto errexit;
 
-    while ((ptr = strtok(NULL, " ")) != NULL) {
+    while ((ptr = potd_strtok(NULL, " ", &saveptr)) != NULL) {
         cnt++;
         if (cnt == 4) {
             mdata.fsname = ptr;
@@ -279,11 +280,11 @@ get_last_mount(void)
         }
     }
 
-    ptr = strtok(NULL, "-");
+    ptr = potd_strtok(NULL, "-", &saveptr);
     if (!ptr)
         goto errexit;
 
-    ptr = strtok(NULL, " ");
+    ptr = potd_strtok(NULL, " ", &saveptr);
     if (!ptr)
         goto errexit;
     mdata.fstype = ptr++;
diff --git a/src/log.c b/src/log.c
index 240c12d..20e9444 100644
--- a/src/log.c
+++ b/src/log.c
@@ -35,6 +35,7 @@
 #include <time.h>
 
 #include "log.h"
+#include "compat.h"
 
 log_priority log_prio = NOTICE;
 log_open_cb log_open = NULL;
@@ -48,12 +49,12 @@ char *
 curtime_str(char *buf, size_t siz)
 {
     time_t t;
-    struct tm *tmp;
+    struct tm *tmp, res;
 
     t = time(NULL);
-    tmp = localtime(&t);
+    tmp = potd_localtime(&t, &res);
 
-    if (!strftime(buf, siz, "%d %b %y - %H:%M:%S", tmp))
+    if (tmp && !strftime(buf, siz, "%d %b %y - %H:%M:%S", tmp))
         snprintf(buf, siz, "%s", "UNKNOWN_TIME");
 
     return buf;
diff --git a/src/main.c b/src/main.c
index 3816a77..9600176 100644
--- a/src/main.c
+++ b/src/main.c
@@ -371,8 +371,8 @@ int main(int argc, char *argv[])
     N("%s (C) 2018 Toni Uhlig <%s>", PACKAGE_STRING, PACKAGE_BUGREPORT);
 #endif
 
-    ABORT_ON_FATAL( selftest_minimal_requirements(),
-        "Selfcheck" );
+    if (selftest_minimal_requirements())
+        exit(EXIT_FAILURE);
 
     if (geteuid() != 0) {
         E("%s", "I was made for root!");
diff --git a/src/protocol_ssh.c b/src/protocol_ssh.c
index 9ad5110..7d6e935 100644
--- a/src/protocol_ssh.c
+++ b/src/protocol_ssh.c
@@ -57,6 +57,7 @@
 #include "pseccomp.h"
 #endif
 #include "options.h"
+#include "compat.h"
 #include "utils.h"
 #include "log.h"
 
@@ -303,16 +304,16 @@ static int gen_default_keys(void)
     char path[PATH_MAX];
     char cmd[BUFSIZ];
     int s = 0;
-    struct passwd *pwd;
+    struct passwd pwd;
 
     errno = 0;
-    pwd = getpwnam(getopt_str(OPT_CHUSER));
+    if (potd_getpwnam(getopt_str(OPT_CHUSER), &pwd))
+        return 1;
+
     if (mkdir(getopt_str(OPT_SSH_RUN_DIR), R_OK|W_OK|X_OK) && errno == ENOENT) {
         if (chmod(getopt_str(OPT_SSH_RUN_DIR), S_IRWXU))
             return 1;
-        if (!pwd)
-            return 1;
-        if (chown(getopt_str(OPT_SSH_RUN_DIR), pwd->pw_uid, pwd->pw_gid))
+        if (chown(getopt_str(OPT_SSH_RUN_DIR), pwd.pw_uid, pwd.pw_gid))
             return 1;
     }
 
@@ -329,10 +330,8 @@ static int gen_default_keys(void)
     }
     if (chmod(path, S_IRUSR))
         return 1;
-    if (pwd) {
-        if (chown(path, pwd->pw_uid, pwd->pw_gid))
-            return 1;
-    }
+    if (chown(path, pwd.pw_uid, pwd.pw_gid))
+        return 1;
 
     snprintf(path, sizeof path, "%s/%s", getopt_str(OPT_SSH_RUN_DIR),
         dsa_key_suf);
@@ -347,10 +346,8 @@ static int gen_default_keys(void)
     }
     if (chmod(path, S_IRUSR))
         return 1;
-    if (pwd) {
-        if (chown(path, pwd->pw_uid, pwd->pw_gid))
-            return 1;
-    }
+    if (chown(path, pwd.pw_uid, pwd.pw_gid))
+        return 1;
 
     snprintf(path, sizeof path, "%s/%s", getopt_str(OPT_SSH_RUN_DIR),
         ecdsa_key_suf);
@@ -365,10 +362,8 @@ static int gen_default_keys(void)
     }
     if (chmod(path, S_IRUSR))
         return 1;
-    if (pwd) {
-        if (chown(path, pwd->pw_uid, pwd->pw_gid))
-            return 1;
-    }
+    if (chown(path, pwd.pw_uid, pwd.pw_gid))
+        return 1;
 
     return s != 0;
 }
@@ -630,7 +625,7 @@ static int auth_password(const char *user, const char *pass,
     size_t i;
     double d;
     time_t o, t = time(NULL);
-    struct tm *tmp;
+    struct tm tmp;
     char time_str[64] = {0};
 
     for (i = 0; i < CACHE_MAX; ++i) {
@@ -644,8 +639,9 @@ static int auth_password(const char *user, const char *pass,
                 strncmp(pass, cache[i].pass, PASS_LEN) == 0 &&
                 strnlen(pass, PASS_LEN) == strnlen(cache[i].pass, PASS_LEN))
             {
-                tmp = localtime(&o);
-                if (!strftime(time_str, sizeof time_str, "%H:%M:%S", tmp))
+                if (!potd_localtime(&o, &tmp))
+                    continue;
+                if (!strftime(time_str, sizeof time_str, "%H:%M:%S", &tmp))
                     snprintf(time_str, sizeof time_str, "%s", "UNKNOWN_TIME");
                 N("Got cached user/pass '%s'/'%s' from %s",
                     user, pass, time_str);
diff --git a/src/utils.c b/src/utils.c
index 3cf88d5..edcfb31 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -63,6 +63,7 @@
 #endif
 
 #include "utils.h"
+#include "compat.h"
 #ifdef HAVE_SECCOMP
 #include "pseccomp.h"
 #endif
@@ -379,8 +380,8 @@ int redirect_devnull_to(int fds, ...)
 
 int change_user_group(const char *user, const char *group)
 {
-    struct passwd *pwd = NULL;
-    struct group *grp = NULL;
+    struct passwd pwd;
+    struct group grp;
     gid_t gid;
 
     if (group)
@@ -388,22 +389,24 @@ int change_user_group(const char *user, const char *group)
     else
         D2("Change user to '%s' and its main group", user);
 
-    pwd = getpwnam(user);
-    if (!pwd)
+    if (potd_getpwnam(user, &pwd)) {
+        E_STRERR("Get uid from user '%s'", user);
         return 1;
+    }
 
     if (!group) {
-        gid = pwd->pw_gid;
+        gid = pwd.pw_gid;
     } else {
-        grp = getgrnam(group);
-        if (!grp)
+        if (potd_getgrnam(group, &grp)) {
+            E_STRERR("Get gid from group '%s'", group);
             return 1;
-        gid = grp->gr_gid;
+        }
+        gid = grp.gr_gid;
     }
 
     if (setresgid(gid, gid, gid))
         return 1;
-    if (setresuid(pwd->pw_uid, pwd->pw_uid, pwd->pw_uid))
+    if (setresuid(pwd.pw_uid, pwd.pw_uid, pwd.pw_uid))
         return 1;
 
     return 0;
@@ -1072,6 +1075,8 @@ int selftest_minimal_requirements(void)
         goto error;
     } else if (s >= 0) {
         close(s);
+        if (chmod(getopt_str(OPT_ROFILE), S_IRUSR|S_IWUSR))
+            goto error;
     }
     if (mkdir(getopt_str(OPT_RODIR), S_IRWXU) && errno != EEXIST) {
         E_STRERR("RO-directory '%s' check", getopt_str(OPT_RODIR));
@@ -1091,6 +1096,17 @@ int selftest_minimal_requirements(void)
         goto error;
     }
 
+    s = -1;
+    child_pid = fork();
+    if (!child_pid) {
+        if (change_default_user_group())
+            exit(EXIT_FAILURE);
+        else
+            exit(EXIT_SUCCESS);
+    } else waitpid(child_pid, &s, 0);
+    if (s)
+        goto error;
+
     /* advanced sandbox tests */
     if (getuid() == (uid_t) 0) {
         child_pid = fork();
@@ -1103,16 +1119,16 @@ int selftest_minimal_requirements(void)
             case 0:
                 if (clearenv()) {
                     E_STRERR("%s", "Clearing environment vairables");
-                    goto error;
+                    exit(EXIT_FAILURE);
                 }
                 if (cgroups_set() || cgroups_activate()) {
                     E_STRERR("%s", "Activating cgroups");
-                    goto error;
+                    exit(EXIT_FAILURE);
                 }
                 if (unshare(CLONE_NEWUTS|CLONE_NEWPID|CLONE_NEWIPC|CLONE_NEWNS))
                 {
                     E_STRERR("%s", "Unshare");
-                    goto error;
+                    exit(EXIT_FAILURE);
                 }
                 mount_root();
 #ifdef HAVE_SECCOMP
@@ -1120,10 +1136,12 @@ int selftest_minimal_requirements(void)
                     (getopt_used(OPT_SECCOMP_MINIMAL) ? PS_MINIMUM : 0));
                 if (pseccomp_default_rules(psc)) {
                     E_STRERR("%s", "Seccomp");
-                    goto error;
+                    exit(EXIT_FAILURE);
                 }
                 pseccomp_free(&psc);
 #endif
+
+                s = -1;
                 child_pid = fork();
                 if (!child_pid) {
                     if (safe_chroot(getopt_str(OPT_ROOT)))
@@ -1137,22 +1155,24 @@ int selftest_minimal_requirements(void)
 #endif
                     exit(EXIT_SUCCESS);
                 } else waitpid(child_pid, &s, 0);
+
                 exit(s);
-                break;
             default:
                 waitpid(child_pid, &s, 0);
+                if (s)
+                    goto error;
         }
     }
 
-    if (getopt_used(OPT_RUNTEST)) {
-        N("%s", "Selftest success");
+    N("%s", "Selftest success");
+    if (getopt_used(OPT_RUNTEST))
         exit(EXIT_SUCCESS);
-    }
+
     return 0;
 error:
-    if (getopt_used(OPT_RUNTEST)) {
-        E("%s", "Selftest failed");
+    E("%s", "Selftest failed");
+    if (getopt_used(OPT_RUNTEST))
         exit(EXIT_FAILURE);
-    }
+
     return 1;
 }